Acetic acid, \( \mathrm{CH}_{3} \mathrm{COOH} \), is a weak acid. What is the reaction of acetic acid in water? \( \mathrm{CH}_{3} \mathrm{COOH}(a q)+\mathrm{OH}^{-}(a q) \rightarrow \mathrm{H}_{2} \mathrm{O}(l)+\mathrm{CH}_{3} \mathrm{COO}^{-}(a q) \) \( \mathrm{CH}_{3} \mathrm{COOH}(a q)+\mathrm{H}_{2} \mathrm{O}(l) \rightleftharpoons \mathrm{H}_{3} \mathrm{O}^{+}(a q)+\mathrm{CH}_{3} \mathrm{COO}^{-}(a q) \) \( \mathrm{CH}_{3} \mathrm{COOH}(a q)+\mathrm{H}_{2} \mathrm{O}(l) \rightarrow \mathrm{H}_{3} \mathrm{O}^{+}(a q)+\mathrm{CH}_{3} \mathrm{COO}^{-}(a q) \) \( \mathrm{CH}_{3} \mathrm{COOH}(a q)+\mathrm{H}_{3} \mathrm{O}^{+}(a q) \rightleftharpoons \mathrm{H}_{2} \mathrm{O}(l)+\mathrm{CH}_{3} \mathrm{COO}^{-}(a q)+\mathrm{H}^{+}(a q) \)

Acetic acid, commonly found in vinegar, exhibits its acidic nature when dissolved in water through the dissociation into hydronium ions and acetate ions. This process is represented by the reaction: \( \mathrm{CH}_{3} \mathrm{COOH}(aq) + \mathrm{H}_{2} \mathrm{O}(l) \rightleftharpoons \mathrm{H}_{3} \mathrm{O}^{+}(aq) + \mathrm{CH}_{3} \mathrm{COO}^{-}(aq) \). Since acetic acid is a weak acid, it does not completely ionize, making this an equilibrium reaction where both reactants and products coexist in solution. For a splash of real-world application, acetic acid’s unique properties make it extremely useful in various industries—from food preservation to cleaning products. It serves as a key ingredient in salad dressings, marinades, and even as a natural disinfectant. Understanding its equilibrium nature helps in culinary practices and industrial processes to achieve desired acidity levels without overpowering other flavors or reactions. So, next time you whip up a salad dressing, remember you’re engaging in a little chemistry!